Gauge unit



Patented Dec. 8, 1953 UNITED STATES PATENT OFFICE GAUGE UNIT Hans J. Lovenston, Detroit, Mich. Application Augustl, 1949, Serial No. 107,846

17 Claims.

This invention relates to a gaging apparatus and has to do more particularly with a gage unit for indicator gaging equipment.

It is an object of this invention to produce a gage unit for an indicator which is constructed so as to be usable with various mountings and measuring extensions for different types of gaging operations; that is. the gage unit of this invention. is provided with a removable base and measuring extensions which adapt it for use as a depth gage, surface gage, or other gages of special design.

Another object of the invention is to produce a gage unit for an indicator designed to permit a measuring extension to be usable over a substantial measuring range.

The invention contemplates a gage unit for an indicator which permits gaging in a new and improved manner and which is constructed to prevent injury to the delicate mechanism of the indicator during both the setting and gaging operations.

It is also contemplated to produce a gage unit on which an indicator is adapted to be mounted, the gage being provided with means permitting the indicator to be optionally connected with or disconnected from the operating mechanism of the gage so that when the gage is being adjusted to the initial setting, the indicator may be disconnected from the gage operating mechanism and the possibility of injury to the delicate mechanism of the indicator is thereby eliminated.

Another object of the invention is to produce a gage unit for an indicator having a reciprocable plunger for actuating the indicating mechanism of the indicator, the plunger being provided with means for adjusting the indicator at a desired setting relative to a fixed position of the plunger.

Another object of the invention is to produce a gage unit for an indicator having a reciprocable plunger arranged to operate the indicating mechanism of the indicator and also having a member associated with the plunger for moving the plunger to and from the work contacting position.

A further object of the invention resides in the provision of means for holding the plunger in a rigid locked position in the body of the'gage so that any shock or strain imparted to the plunger will be absorbed by the body of the gage unit and not transmitted to the delicate operating mechanism of the indicator with which the plunger is operatively connected.

In the drawings:

Figure 1 is a front elevation of the gage unit 2 of this invention, shown as it is used with a dial indicator and positioned on a master setting gage. Figure 2 is a side elevation, partly in section of the gage unit assembly shown in Figure 1.

Figure 3 is a fragmentary sectional view take along the lines 3--3 in Figure 2.

Figure 4 is a fragmentary end view of the gage unit showing the locking plunger handle.

Figure 5 is a fragmentary sectional view showing a modified form of plunger locking member. In the drawings, the gage unit of this invention is shown in conjunction with a dial indicator Ill. The indicator 10 does not form a part of this invention, but since my gage is shown for use with a dial indicator, its construction will be briefly described. It includes a casing H which houses an indicating mechanism which when actuated causes the pointer or arrow l2 to indicate a reading on the graduated face I3 of the dial. The indicating mechanism includes a pinion 9 which is arranged to be actuated by a rack 8 on a stem M which is reciprocably mounted and biased to project outwardly of easing ll within a sleeve I5. Pinion 9 is, of course, .operatively connected with pointer l2 through some delicate mechanism not shown. The particular dial indicator illustrated and the operating mechanism therefor are of conventional design and are shown merely for the purposes of illustration, it being understood that the gage unit of this invention is adapted for use with indicators of different construction. The gage unit of my invention comprises a body [6 which is provided with a central bore IB extending through body It from the upper to the lower face thereof, l9 and 20 respectively. Within bore [8 there is slidably arranged a plunger 22 having a close lit with the cylindrical wall of bore It). At its upper end plunger 22 is provided with a central socket 23 having a reduced portion 24 which is threaded to receive an adjusting screw 25. The lower end of plunger 22 is provided with a threaded bore 26 of greater diameter than the reduced portion 24 and providing access to the head of screw 25 from the lower end of the plunger. Within the threaded bore 26 at the lower end of plunger 22 there is threaded a plunger extension 21 which in turn is adapted to receive a further extension 28 as by means of the threaded socket 29 at the lower end of extension 21.

Dial indicator Ill is arranged to be supported on body l6 by means of a cap member 30 which is secured on body 16 as by cap screws 3!. On its lower face cap 30 is provided with a centrally 3 disposed pilot 32 which projects into and has a close fit with the upper end of bore it! in body IS. The upper portion of cap 30 is provided with a split bearing 33 concentric with pilot 32. Bearing 33 is adapted to receive sleeve 15 of indicator ID with stem [4 projecting into socket 23' at the upper end of plunger 22. Stem l4 and plunger 22 are adapted to be operatively connected as by threading screw 25 upwardly until the upper end of the screw contacts the lower end of the stem.

Bearing 3'3 "is arranged to be contracted and clinched arou'nd sleeve l5 by screws 34 which extend across the split portions of the bearing. A guard 35, extending around the exposed portitins .having a planar gaging surface 65 on the lower 7 facethereof is secured on the lower face 20 of bf the indicator, is supported on body I5""by' screws 36. v

Plunger 22 is normally biased in a downward direction by means of a pairofcoilspring's 413 which are retained within centrally offset sockets 4| in the plunger and ;which act between the lower end of sockets 4| and the lower face of pilot'32 as is best shown'in'liigure 2,. A b i'ifiending transversely throughbore i8 is e within'a recessed slot 3 in 'plu'ng'er22 to limit the extent' of upwardly and downwardly movement 25 shaped'headportion mean be advancediritoior 3,5

retracted out 'of conical opening as in plunger 22." Screw 47 is adjustable inwardly and out wardly 'to limit the movemen'tpf plunger 22 in an upwardly direction by "contact with the lower inclined wall of opening 2-5; 'SQ'of locking stud or plunger 52 projects into opening 56. Plunger '52 is s'lidabl'y arranged withinja bore 53 in'body l$ which extends inia direction transversely of and intersects with bore 1 Plunger 52 is normally biased inwardly intofengagement with the upper inclined WQQHQf qpeningle'by means of a compression spring 5% which disposed within an axially'extending socket '55 within theplunger 52. Spring 5% acts i g th" 1l' k a 31 3 22 id g g f fi g g g gg e i g ggig no adjusted to a particular setting, the dial indicator which eitends transversely through" bore "53 and anjelongate slot 5'5 in plunger 52. Plunger 52 1s arranged to be retracted out of engagement with thei'inclined wall of opening at by means'of'a handle '58 which is pivotally mounted at the'outer en'd'of plunger 52'as 'by a pin 5S3. Handle 58'is fashioned at one endwith a cam surface 66 which, when the handle "is pivoted to the horizontal positi'on, engages the outer end face -of body 16 and shifts plunger 52 outwardly. It will be noted that when handle 58 is released to engage the conical head 5!} of plunger 52 with the upper inclined-wall of opening it, plunger 22 is forced upwardly until contact is established between thelower inclined wall of opening #25 and the com cal end 48 of stop screw 41 and plunger 22 is thereby effectively locked in hore'ilB:

In Figure 5 there is illustrated-a modified form of locking member for plunger 22.- In this modification a screw 6| having a conically' shapedv head 62 isthreaded into body IG'rso that the conically shaped head 52 can be advanced into engagement with theupper inclinedwall of opening 46; At its outer' end-screw BI is providedwith "75 The conical end [6 as by cap screws 66. It will be apprepie-ted; of course, that the lower face 26 of body I 6 may be employed as the planar gaging surface ifdesiredftheremovable base $4 being provided sirnplyto render the gage more universal in use. Base 64 'is centrally apertured as at 5'? to receive plungerextensions 21 and 28, the gaging surface being machined to lie in a plane perpefidiciilar tothe' 'aiiis I of here it. n willfb appreciated that other bases may be provided for ti t gage unit for other types It will also be noted that w W of plunger extensions may vary widely design {according to the'requirements of'a particular gaging operation and that plunger 22 may be employed to fulfill the functions of extensions "27 and zs-ey simply eiitending "the lowhend thereof 'threduired distance, below gaging surface 65 or the lower face '26- on body it.

When it is desired to set the gage for measuringthe'depth'of a hole or the like in a work piece," plunger extensions 21 and 2% arefir s't removed from the end of plunger 22. Fcrthis purpose theplungerextensions are provided with transverse holes 69 through which a rod or like tool can be inserted for turning the extension. Plunger 22 is prevented from turning by means ofpin 42 which is engaged within recess '43. After extensions 27 and 23 are removed from the end of the plunger ascrew driver is inserted into bore-26 at the lower end of the plunger and "screw 2 5"is withdrawn out of contact with the *stemidf'of' the indicator while the plunger is in lthe locked position as shown in Figure '3. It wilt be appreciated that this precaution is taken so-that while plunger 22 is subsequently'being iseffectively disconnected from the gage and any shock on plunger 2-2 will not be transmitted tostem i4 and in turn to thedelicate indicating mechanism citric-indicator. The'pcssibiiity of strainand injury to: the indicator due to over travel of stem ]4. beyond the range limit of the indicator is also eliminated; Extensionszi and 28, having been; previously selected as falling-within the range of measurement desired, are then reassembled on plunger 22;; In this conditionthe gage assembly is placed-upon a master set up gage I0 withthe gaging surface'65 of base Efi'resting pn one functional surface ii of the master gage.

Handle 58 is thenpivoted downwardly tofitetra-ct plunger 52 and permit plunger 22 and extensions '23-; and; 28 to move downwardly --under theinfluence of compressionsprings-e 8 thelower end of extension; 218; contacts theother-functional surface ,12-of'; the-master gage. Surfaces? and 12-, are, of course; spaced. perpendicularly apart a distance corresponding to the correct: depth of the, surfaces to be measured on the-work piece.

The return stope'screw' l! is: then threaded; i'nwardly until its conical head poiticnflltr-eontacts the lower" inclinedi wallr "offopening 145. Y

After the age has been initially set in this manner, plunger extensions 21 and 28 are again removed. A screw driver is then inserted in threaded bore 26, engaged with the end of adjusting screw 25 and pushed inwardly of the gage body until the lower inclined surface of opening 45 contacts the conical end portion 48 of screw 41. With the plunger in this position, adjusting screw 25 is threaded inwardly until contact is established with the end of stem I4. The inward adjustment of screw 25 is continued to a point where arrow I2 indicates on the face of the dial that approximately half of the total range of the indicator has been reached. Plunger extensions 21 and 28 are again reassembled on plunger 22 and return stop screw 41 is withdrawn slightly so as to permit the plunger to move upwardly beyond its previous setting but to a point within the safe operating range of the indicator which can be determined by the reading of pointer I2 on the face of the dial. This permits both the plus and minus dimensional variations of the work piece to register on the indicator dial. It will also be noted that adjusting screw 25 is in a tamper proof enclosure after assembly of extensions 21 and 28 on plunger 22. After screw 47 is withdrawn handle 58 is released to permit plunger 52- to move inwardly under the influence of compression spring 54. In so doing, the conical head 58 of plunger 52 engages the upper inclined surface of opening 46 and holds plunger 22 in a retracted and locked position.

The gage is then placed on the master set up gage as previously described and handle 58 is slowly pivoted downwardly so that plunger 22 is is permitted to move slowly in a downward direction under the influence of springs 48 until the lower end of extension 28 contacts the lower functional surface 12 of the master gage. The indicator dial I3, which is adjustable in a rotary direction by turning an outer rim member 13, is then rotated so that the zero mark coincides with arrow I2. The dial is locked in this position by means of a locking screw 14. Thereafter looking handle 58 is again released to permit plunger 52 to move inwardly and thereby force plunger 22 upwardly until the lower in clined face of opening 45 engages the conical head 48 of stop screw 41. The gage is then in a set condition for checking the desired dimensions-of the work piece. Screws 25 and 41 are initially slotted and expanded as at 16 and 11, respectively, to obtain a substantial friction tight fit so that they will not be accidentally moved out of adjustment.

In checking the dimensions of a work piece, the gage is set on the work piece with gaging surface 65 of base 64 resting on the accurately machined surface of the work piece from which the desired distance of the other surface is to be measured. In order to facilitate handling of the gage conveniently, body I6 is recessed at each side thereof as at 15 at which portions the gage may be gripped firmly. Plunger 22 is then released by pivoting handle 58 downwardly,- or in the case of the modified construction shown in Figure 5, by turning knob 63 so as to thread screw 6| outwardly. Plunger 22 is thereby forced downwardly by springs 48 until the lower end of extension 28 contacts the bottom of the hole or other surface being gaged. The distance between thetwo surfaces will then be indicated by the position of the indicator pointer with reference to thezero mark on the dial.

. It will be appreciated that since the plunger assembly'aiways moves downwardly from the locked position, the gage unit of this invention provides a more. uniform mode of gaging since the velocity of the downward movement of the plunger can be readily controlled by regulating the rate at which the locking plunger 52 or locking screw 6I is withdrawn from engagement with plunger 22. This controlled release of plunger 22 has an important effect on the indicator mechanism since uncontrolled velocities of the plunger will have a tendency to prevent accurate repetition of the indicator reading. It will also be observed that withplunger 22 in the locked condition any shock on the plunger extensions will be absorbed by the body I6 of the gage and prevented from being transmitted through stem I4 to the operating mechanism of the indicator. Return stop 41, it will also be noted, prevents overtravel of plunger 22 which might otherwise result in injury to the operating mechanismof the indicator.

It will also be noted that the positioning of the conical end portion 48 of return stop screw 4'! in relation to the lower inclined Wall of opening 45 in plunger 22 and the positioning of adjusting screw 25 in relation to the end surface of indicator stem I4 permits the positioning of the lower end surface of plunger 22 in relation to base surface 28 on body I6 over a substantial range and thus permits the use of plunger extensions such as 2! and 28 to be used for measurements which fall within this adjusting range of the gage unit.

Since the adjustment range of the gage unit is limited, interchangeable plunger extensions are provided to permit use of the gage with work pieces of widely different dimensions and designs. The lengths of these plunger extensions will be in increments equal to the total adjustment range of the gage so that when the maximum or minimum limit of the gage adjustment has been reached with a particular extension a new extension may be mounted on the plunger which will have a dimension suitable for measuring the particular work piece desired.

It will thus be seen that I have provided a gage gage unit to be used interchangeably with gages: of diiferent base constructions and with plunger extensions of different design and dimensions: to suit a multitude of gaging requirements. This permits standardization of this gage unit, and is conducive to economy in the maintenance and construction of gaging equipment.

I claim:

1. A gage unit for use with an indicator of thetype having a reciprocable stem and an indicating mechanism arranged to be actuated by said stem comprising a body having means thereon for supporting said indicator, an axially slidable plunger in said. body, means for connecting said plunger with said stem so that said indicating mechanism is actuated by said plunger when the plunger moves in one direction, stop means on said body engageable with said plunger for limiting the axial movement of said plunger in said one direction toa position within the-operatingrange of said indicator whereby when said plunger is engaged againstsaid stop, shocks imparted to said plunger are absorbed by said body and prevented from being transmitted to said stem and indicating mechanism, and including resilient means on said body acting on and biasing said plunger in a direction opposite to said one direction and includingcam'means on said body engageable with said plunger to move said plunger in said one direction to a position engaging said stop means and being movable to release said plunger, whereby when said cam means are released said plunger moves in said opposite direction under theinfluence of said resilient means.

2. The combination set forth in claim 1 wherein said plunger and cam means are operatively connected such that said plunger is movable under the influence of said resilient'means in a direction outwardly of said'body in response to movement of said cam means whereby the velocity with which said plunger moves outwardly from said position in engagement with said stop means under the influence of said resilient means may be controlled by controlling the rate at which said cam means "are moved to release said plunger.

'3. The combination-set forth in claim 1 where'- in said stop means on said body limits the movement of said plunger in a direction inwardly of said body to a predetermined adjustable position within the range of movement of said indicating mechanism.

'4. In combination with an indicator of the type having a reciprocable stem and an n a a ing mechanism arranged to be operated by said stem,- a gage unit comprising a body, means on said body for supporting said indicator, a plunger in said body axially slidable in a direction inwardly and outwardly of said body, means for operatively connecting said stem and plunger so that said indicating mechanism is actuated by said plunger when the plunger moves inwardly of the body, stop means on said body for limiting the axial movement of said plunger in a direction inwardly of the'body to a predetermined adjustable position within -.the operating range of'said indicating mechanism, said connecting means being accessible and actuatable to disconnect said stem and plungerwhile said indicator is supported bysaid body and said plunger is slidably engaged in said body so that said indicating mechanism will not be responsive to movement of said plunger, whereby when said gage is being adjusted for a work piece of particular dimension, said connecting means may be actuated to disconnect said plunger from said stem prior to adjustment of said step means to the desired setting within the operating range of said indicating mechanism, and when said stop means are adjusted to the desired setting and said connecting means actuated to connect said plunger and stem, said plunger is thereafter prevented from moving axially in an inwardly direction to a position beyond the operating range of said indicating mechanism.

5. The combination set forth in claim 4 wherein said means for operatively connecting said plunger andstem comprise a screw threaded on said plunger and engageable with the end of said stem, said-screw being adjustable to shift said stem axially to obtain an initial setting of said'indicating mechanism and being retractable to a position tree of said stem when the plunger is in its -innermost position in said body whereby 8*. when-said screw is adjusted :to said position free of saidstemgsaid indicat ng mechanism is weft-- fectively disconnected from and incapable ofbeing actuated by said plunger.

6. The'combination as set forth in claim 4 including an extension member removably secured to one end of said plunger, said extension member having the end thereof forming a work contacting surf-ace.

'7. A gage unit comprising a body having a bore therein; a plunger slidable-axially within said bore and having one end thereof projectable in a direction outwardly of said body, anindicating device operatively associated with said plunger, a stop onsaid body for limitingpthe movement of said plunger inwardly of said body, and releasable means on said body engageable with said plunger for retaining said plunger against said stop, whereby when said releasable means are actuated to retain said plunger against said stop any shock to the projecting end of said plunger tending to move said plunger axially inwardly is absorbed by said body and not trans-- mitted to said indicating device.

8. The combination set forth in claim 7 where-' in said releasable means comprises a stud on said body movable in a rectilinear path transversely of the path of movement of said plunger, said plunger having a generally V-shaped notch therein, said stud being movable to a position where the end of said stud projects into and is engaged by said V-shaped notch to retain said plunger against saidstop.

9. The combination set forth in claim 7 including resilient means acting on and biasing said plunger in a direction outwardly of said body, said plunger provided with a notch therein having a sidewall inclined to the axis .of the plunger, said releasable means comprisinga stud in saidbody movable in a direction transversely of-the axis of said plunger and having an end portion thereofengageable with the inclined side wall of said notch to limit the movement of said plunger in an outward direction, said stud being movable toretract said-end portion out ofsaid notch, whereby as said stud is retracted, said biasing means urge said plunger outwardly and maintain said inclined side wall in engagement with said end portion of said stud whereby the rate at which said plunger moves outwardly may be controlled by the rate at which said stud is retracted.

10. In combination with an indicator of the type having a reciprocablestem and an indicat- V ing mechanism arranged to be operated by said stem, a gage unit comprising a body having a bore therein, means on said body for supporting the indicator-thereon, a plunger slidable axially in said bore, a screw threaded in one end offsaid plunger and having an end portion engageabie with the end of said stem so as to actuate said stem in response to axial movement of said plunger, said plunger having a socket at the other end thereof providing access to -the'head of said screw whereby when said plunger isin a fixed position in said bore, said screw may be adjusted to vary the setting of said indicating mechanism relative-to said fixed position of said plunger.

11: In combination with anindicator having an axially reciprocable stem arranged to operate an indicating mechanism, a gage unit comprising a body having an axially'slidable plunger therein, means for mounting said indicator on sa d-body. said. body having a--planar gag-ing surface, said plunger being slidable in a direction transversely of said gaging surface, means including a screw threaded into said plunger and contacting the end of said stem for operatively connecting said plunger with said stem, means on said body forming an opening through which said screw is accessible when said indicator is mounted on said body, said screw being adjustable to vary the setting of said indicating mecha nism relative to said plunger.

12. A gage unit comprising a body having a bore therein, a plunger slidable axially within said bore, resilient means acting on and biasing said plunger axially in one direction, said plunger having a notch therein presenting a surface angularly inclined to the axis of the plunger, said body having a second bore intersecting said first bore and inclined axially to the plane of said inclined surface, and a detent movable axially in said second bore, said detent having an end portion engageable with and disposed in the path of movement of said inclined surface, said biasing means biasing said plunger into engagement with said detent whereby when said detent is moved in said second bore toward and in engagement with said inclined end surface, said plunger is shifted axially in one direction by reason of the engagement of the end portion of said detent with said inclined surface and when said detent is moved in a direction away from said inclined surface, said plunger is shifted under the influence of said biasing means in a direction opposite to that previously mentioned.

13. In combination with an indicator of the type having a reciprocable stem and an indicating mechanism arranged to be operated by said stem, a gage unit comprising a body having a planar gaging surface, means for supporting said indicator on said body, a plunger slidable axially in said body along a path substantially perpendicular to said gaging surface, means for operatively connecting said plunger and said stem so that said stem is actuated in response to axial movement of said plunger, said connecting means being adjustable to set said indicating mechanism at a predetermined initial setting for different positions of said plunger, means on said body providing an access opening for said connecting means to enable adjustment thereof while the indicator is supported on the body, and stop means in said body for limiting the axial movement of said plunger to a predetermined adjustable position whereby after said stop means are adjusted to limit the movement of said plunger to a desired position, said connecting means may be adjusted through said access opening to set said indicating mechanism to said initial setting so that displacement of said plunger from said predetermined position is indicated by the deviation of said indicating mechanism from 15. The combination set forth in claim 13 wherein said connecting means comprises a screw threaded on said plunger and advanceable into and out of engagement with an end of said stem.

16. In combination with an indicator of the type having a reciprocable stem and an indicating mechanism arranged to be operated by said stem, a gage unit comprising a body having a bore therein, means on said body for mounting said indicator thereon, a plunger slidable axially in said bore in a direction inwardly and outwardly of said body, means operatively connecting said stem and said plunger so that said indicating mechanism is actuated by said plunger when the plunger moves inwardly of the body, stop means on said body engageable with said plunger for limiting the movement of said plunger in a direction inwardly of the body to a predetermined adjustable position within the operating range of said indicating mechanism whereby overtravel of said plunger in an inwardly direction and consequent injury to said indicating mechanism is prevented, said plunger being provided with a pair of opposed surfaces angularly inclined relative to the axis of the plunger, and a pair of stud members on said body movable axially into engagement with said opposed inclined surfaces, said stud members having end portions providing surfaces inclined similarly to said opposed surfaces for engagement therewith, one of said stud members and opposed surfaces comprising said stop means and the other of said stud members and opposed surfaces providing means for retaining said plunger against said stop means.

17. In combination with an indicator of the type having a reciprocable stem and an indicating mechanism arranged to be operated by said stem, a gage unit comprising a body having a bore therein, means on said body for mounting said indicator thereon, a plunger slidable axially in said bore in a direction inwardly and outwardly of said body, means operatively con necting said stem and said plunger so that said indicating mechanism is actuated by said plunger when the plunger moves inwardly of the body, stop means on said body engageable with said plunger for limiting the movement of said plunger in a direction inwardly of the body to a prededetermined adjustable position within the operating range of said indicating mechanism whereby overtravel of said plunger in an inwardly di rection and consequent injury to said indicating mechanism is prevented, said plunger being provided with a pair of opposed conical openings, a pair of axially movable stud members on said body, said stud members having conical end portions engageable with the walls of said conical openings, and means biasing said plunger in a direction outwardly of said body, one of said stud members and conical openings comprising said stop means and the other of said stud members and conical openings providing means for holding said plunger in a retracted position in said body.

HANS J. LOVENSTON.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,683,710 Zitzmann Sept. 11, 1928 2,324,998 Dague July 20, 1943 2,401,085 Lo Valley May 28, 1946 

